• Journal of agriculture & life science
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• v.52 no.6
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• pp.111-125
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• 2018

In this study, we evaluated the uniformity of deposition rate and particle size distributions of the variable rate application technique using the unmanned rotorcraft by measuring the spray pattern according to path location in the range of spraying flight. The coefficient of variation (CV) of the lateral coverage rate for the overlapped distribution with the spray swath of 3.6 m in both guidance and auto-pilot flight modes maintaining constant flight speed was about 30% and the CV of the coverage rate by the flight path location was extremely small. Therefore, it was assessed that the variable rate application technology compensating for the variation of ground speed was superior in terms of spray uniformity. In addition, the droplet size distributions in both volume median diameter(VMD) and number median diameter(NMD) were adequate for aerial application and uniform in terms of lateral distribution. Thereafter, we intend to contribute to a precise application on small-scaled fields using the unmanned agricultural rotorcraft by the variable rate application.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.291-297
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• 2019

Since Metcalfa pruinosa was first reported in Koera, it has continually caused damage to sweet persimmon orchard in southern part of Korea. Metcafa pruinosa exist not only in farmland but also in forest areas, and are difficult to control due to the influx of individuals from near forest. M. pruinosa has been occurred in orchard and its surroundings because of various host range. Thus, it has been difficult to decide spatial range and control time for efficient management. In this study, occurrence and dispersal pattern of M. pruinosa in persimmon orchard were surveyed using clear sticky traps, and spatial patterns were analyzed with SADIE(Spatial Analysis by Distance IndicEs), based on location information at sticky traps. Spatial association between survey time was also analyzed to identify when the spatial pattern changed. In sweet persimmon orchard, M. pruinosa mainly dispersed in mid to late May, when the first instar hatches, and in August, emerging season of adult. The first instar nymphs hatched in mid-May were randomly distributed in orchard, but distribution was changed to aggregative pattern after dispersed surroundings of orchard. Adults showed random distribution pattern after immigration to orchard again. These tendency was also observed in density change at orchard and its surroundings, and matched to actual density of M. pruinosa in sweet persimmon trees.

• Korean Institute of Interior Design Journal
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• no.28
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• pp.140-148
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• 2001

The purpose of this thesis is to provide basic information of efficient flow line arrangement, which results from examining the factors of route choice with a focus on the store' space elements and pedestrian activity patterns in the outlets. The route tracking is applied to grasp pedestrian activity patterns, therefore, a concrete analysis into influential factors of the space structure arrangement and forms on route choice. The route tracking is a means to understand pedestrian activity patterns by establishing an unrecognizable space and examining every route in the investigating area for pedestrian activity pattern research. Three sample stores have different systems in the ground plan structures, the escalator location and the directions. The analysis focuses on the booth arrangement and shopping patterns. In conclusion, route choice of the customers and the structure of the space are quite closely related and affect the quality of shopping. This can suggest evidence for the need of the space structure to meet the pedestrian activity patterns.

• The KSFM Journal of Fluid Machinery
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• v.2 no.3 s.4
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• pp.17-23
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• 1999

In the present numerical analysis, investigation of the effect of blade loadings from design shape on the slip factor variation was studied. Both the Eckardt radial bladed impeller and the backswept impeller were analyzed. In addition, a new design of the blade profile was arbitrarily attempted to generate a center-loading pattern in the original backswept impeller. Three dimensional compressible Navier-Stokes flow analysis with the Baldwin-Lomax turbulence model was applied to get the numerical slip factor at each impeller exit plane using the mass-averaging technique. The numerical slip (actors are in good agreement with the experimental ones and the Wiesner's slip factors deviate further from the numerical and experimental ones in both backswept impellers. Deviation angles and meridional channel loadings are found in no relation with the trend of change of the slip factor. Blade-to-blade loadings in midspan location are, however, found to have a direct relationship, especially at the sections where maximum loadings we to be expected. That information can be utilized in establishing an improved expression for slip factors in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.29-44
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• 1991

The purpose of this study is to investigate the maximum rate of daily users and the turnover rate of parks in Korea. Median calculation, percentile analysis, and regression analysis methods were adopted for the investigation of the maximum rate of daily users. The maximum level, adaptable level and current dispersion of each index were analyzed. The results are summarized as follows. 1) It is location, kinds of facility, and purpose of visiting that mainly affect the concentration pattern of the number of park users. 2) Parks are devided into such three types as common urban park, royal tomb park, and large amusement park. 3) Spring is the peak season in all parks. 4) The maximum daily rates of the three types of parks are 0.92%, 1.86%, 1.18% respectively and the turnover rates are 18%, 54%, 63% respectively. 5) The results of this study show the necessity of the revision of the existing maximum daily rate and turnover rate.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.201-204
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• 2008

Vortex and swirl occurring in a pump suction intake sump normally reduce the performance and disturb the safe operation of the circulation water pump in thermal power plants. This paper presents a case study of one particular intake sump design via a CFD analysis and a hydraulic model testing. The physical experiments and numerical analysis were performed under two flow and three level variation conditions. The vortex patterns around the pump suction pipe have been predicted by a commercial CFD code with the k-${\varepsilon}$ model. The model tests were conducted on a 1/10 model for a practical intake sump. The location, number and general pattern of the free surface vortex and submerged vortex predicted by CFD simulation were found to be a good agreement with those observed in the model testing.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.304-307
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• 2008

Two-dimensional Stokes flow due to the line source and line sink of same strength in semi-infinite flow region with free surface is analysed using complex variable theory and conformal mapping. Surface tension effects are included while gravity is neglected. From the results of analysis, flow pattern and free surface shape are obtained and velocity distribution on the free surface is determined with 2 independent parameters Ca (capillary number) and h (non-dimensionalized distance between source and sink). When the location of the sink is above the source, velocity on the free surface converges and a cusp occurs on the free surface for the value of Ca above some critical capillary number.

• Journal of Korea Multimedia Society
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• v.18 no.2
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• pp.233-243
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• 2015

A hotspot is a spatial pattern that properties or events of spaces are densely revealed in a particular area. Whereas location information is easily captured with increasing use of mobile devices, so is not our emotion unless asking directly through a survey. Tweet provides a good way of analyzing such spatial sentiment, but relevant research is hard to find. Therefore, we analyzed hotspots of emotion in the twitter using spatial autocorrelation. 10,142 tweets and related GPS data were extracted. Sentiment of tweets was classified into good or bad with a support vector machine algorithm. We used Moran's I and Getis-Ord $G_i^*$ for global and local spatial autocorrelation. Some hotspots were found significant and drawn on Seoul metropolitan area map. These results were found very similar to an earlier conducted official survey of happiness index.

• International Journal of Contents
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• v.17 no.4
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• pp.16-34
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• 2021

The purpose of this study was to explore how designers use software-based design tools for ideation and collaboration (for two cases: with designers and with developers). We conducted logistic regression analysis and random forest analysis. Software-based design tools are more popular among product designers and affiliated with design organizations with 51 to 100 members. We identify the features that influence designers to use design tools for the ideation and collaboration, and how these usage patterns are interrelated. Interrelated usage pattern is a key consideration for location of the menu and convenience of use. The results imply that reinforcement of the design tool features per designer profile is required and that design management should be consistent with the field of design and the nature of the organization.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.182-193
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• 2011

In order to compare the spatio-temporal variation pattern of sea surface temperature (SST) in Korea's Southern areas of the sea according to a regional scale, this study has selected the winter and summer seasons for 31 years (1980~2010) in a period aspect and selected three areas of the sea such as the Western areas of the sea (region B) and Eastern areas of the sea (region C) around Jeju Island in addition to overall Southern areas of the sea (region A) in regional aspect. The regression analysis was applied to find out a temporal variation pattern of SST, and the weighted mean center (WMC) of SST as well as analysis of a standard deviational ellipse (SDE) was respectively applied. As a result of regression analysis of SST, it showed a rising long-term trend for all two seasons in three regions. However, though the average SST for 31 years was all similar in three regions in the summer season, the region C appeared more highly than region B in the winter season. The spatial variation pattern of SST for two seasons showed that it is respectively different from each other in three regions. The spatial variation pattern of SST appeared as E-W direction in region A, SE-NW direction in region B and SW-NE direction in region C. In addition, the relationship between the location of the WMC of SST and the average SST showed correlation in regions A and B in the winter season, whereas it appeared that there is no correlation in region C. Accordingly, it can be known that the regional scale should be considered in case of analysis of spatio-temporal variation patterns of SST.